The arrest rates of juveniles in San Diego County took a dramatic slide over a decade, according to research findings released last week.

The rate of minors hauled off in handcuffs dropped 66 percent between 2007 and 2016, San Diego Association of Governments, or SANDAG, reported in its annual study examining arrest rates by local law enforcement agencies.

Even with the drop, the county still has the second highest rate of arrests — for juveniles and for adults — when compared to the five largest Southern California counties. San Bernardino topped the list for both juvenile and adult arrests.

The findings come from data SANDAG analyzed from California’s Department of Justice. The data includes information through 2016.

Cynthia Burke, director of SANDAG’s Criminal Justice Research Division, said some of that decrease in arrests of juveniles could be the result of an increased focus on prevention and diversion activities.

Other highlights of the report include a 3 percent increase in arrests of juveniles for drugs or alcohol from 2015 to 2016. But, according to the findings, marijuana arrests for juveniles jumped 18 percent.

As with the arrests of juveniles, the numbers of adult arrests is also down, at a 10-year low.

Burke noted that with the approval of Proposition 47 in 2014, the state downgraded a number of property- and drug-related crimes from felonies to misdemeanors.

The year 2015 saw a 28 percent plunge in felony arrests, and an 11 percent increase in misdemeanor arrests — not an unexpected shift given the change in crime classifications.

But in 2016, the misdemeanor arrest rate dropped by 4 percent in the county. It’s not clear why.

That same year, adults in the region were most frequently arrested for drug or alcohol-related offenses, including drunken driving.

Between 2012 and 2016, the county also saw a 34 percent increase in the number of people arrested for skipping court. That, Burke said, suggests that some of the people who were cited instead of arrested may be failing to show up for scheduled hearings.

Proposition 47 addressed drug and property crimes, which are often linked.

“Because we know that substance abuse and crime, especially property crime, can be related, it is important to remember that the need to offer substance abuse treatment continues to be important, regardless of how the crime is classified,” Burke said in an email.

She said that people in the justice field must “continue to work collaboratively and with the community to engage those who have underlying needs that can be addressed.”